The black-headed sugar ant (''Camponotus nigriceps''), also known as the brown sugar ant, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

Formicinae The Formicinae are a subfamily within the Formicidae containing ants of moderate evolutionary development. Formicines retain some primitive features, such as the presence of cocoons around pupae, the presence of ocelli in workers, and littl ...

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

endemic to

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. Found throughout most states, the species is a member of the genus ''

Camponotus Carpenter ants (''Camponotus'' spp.) are a genus of large ants (workers ) indigenous to many parts of the world. True carpenter ants build nests inside wood, consisting of galleries chewed out with their mandibles or jaws, preferably in dead, ...

'', a

cosmopolitan Cosmopolitan may refer to: Internationalism * World citizen, one who eschews traditional geopolitical divisions derived from national citizenship * Cosmopolitanism, the idea that all of humanity belongs to a single moral community * Cosmopolitan ...

genus of ants commonly known as carpenter ants. It was formally described and named by British entomologist Frederick Smith in 1858. These ants are characterised by their black head, reddish-brown

mesosoma The mesosoma is the middle part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the metasoma. It bears the legs, and, in the case of winged insects, the wings. Wasps, bees and a ...

and black gaster, which can change in colour. The species is polymorphic: workers and soldiers measure and males are . The queens are the largest members of the colony, measuring . Colonies dwell in dry regions, including open areas or in dry sclerophyll woodland, where they nest in soil, large mounds or under stones.

Nuptial flight Nuptial flight is an important phase in the reproduction of most ant, termite, and some bee species. It is also observed in some fly species, such as '' Rhamphomyia longicauda''. During the flight, virgin queens mate with males and then land ...

occurs in summer and nests can hold several thousand individuals. Considered a household pest, black-headed sugar ants feed on sweet foods and insects and tend to butterfly larvae. Numerous birds and fish prey on these ants.

Taxonomy

The black-headed sugar ant was described from a

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

worker by British

entomologist Entomology (from Ancient Greek ἔντομον (''éntomon''), meaning "insect", and -logy from λόγος (''lógos''), meaning "study") is the branch of zoology that focuses on insects. Those who study entomology are known as entomologists. In ...

Frederick Smith in his 1858 publication ''Catalogue of the hymenopterous insects in the collection of the British Museum. Part VI. Formicidae'', and was originally placed in the genus ''

Formica ''Formica'' is a genus of ants of the subfamily Formicinae, including species commonly known as wood ants, mound ants, thatching ants, and field ants. ''Formica'' is the type genus of the Formicidae, and of the subfamily Formicinae. The type ...

''. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''nigriceps'', is derived from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

words ''niger'' black", and ''ceps'', abbreviated form of ''caput'' "head" when used in a compound word. Some years later, the species was assigned to the genus ''

'' by German entomologist

Julius Roger Julius Roger (23 February 1819 – 7 January 1865) was a German Physician, medical doctor, Entomology, entomologist, and Folklore, folklorist who worked in Racibórz, Ratibor, in Upper Silesia, most notable for having arranged (and raised the nec ...

. In 1887, Italian entomologist

Carlo Emery Carlo Emery (25 October 1848, Naples – 11 May 1925) was an Italian entomologist. He is remembered for Emery's rule, which states that insect social parasitism (biology), social parasites are often closely related to their hosts. Early in hi ...

described a

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

, ''Camponotus nigriceps lividipes'', based on collections of smaller ants. In 1933,

William Morton Wheeler William Morton Wheeler (March 19, 1865 – April 19, 1937) was an American entomologist, myrmecologist and professor at Harvard University. Biography Early life and education William Morton Wheeler was born on March 19, 1865, to parents Juliu ...

classified the black-headed sugar ant as a subspecies of the banded sugar ant (''Camponotus consobrinus''), but it was later revived as a full species in 1934. The ant is a member of the ''Camponotus nigriceps''

species group In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

, which also includes '' C. clarior'', ''C. consobrinus'', '' C. dryandrae'', '' C. eastwoodi'', '' C. loweryi'', '' C. longideclivis'', '' C. pallidiceps'' and '' C. prostans''.

Description

Camponotus nigriceps casent0280197 profile 1

Ants of this species are relatively large; it is a polymorphic species with two castes of workers, known as minor workers and major workers (soldiers). Workers and soldiers range in sizes from . Males measure and queens are the largest, measuring . Workers and soldiers of the subspecies ''Camponotus nigriceps lividipes'' only grow to . Workers' gasters and mesosomi can vary in colour; the gaster can be black, brown or yellowish-brown while the mesosoma is either reddish-brown or yellow. Workers are mostly brown with light patches noticeable on the head and mesosoma, and their clypei and

mandibles In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

are even darker; the

legs A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element cap ...

are either black or brown. A large number of hairs grow from the gaster,

mesonotum The mesothorax is the middle of the three segments of the thorax of hexapods, and bears the second pair of legs. Its principal sclerites (exoskeletal plates) are the mesonotum (dorsal), the mesosternum ( ventral), and the mesopleuron (lateral) ...

pronotum The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum (dorsal), the prosternum (ventral), and the propleuron (lateral) on e ...

and

propodeum Propodeum labelled within the alitrunk of an ant worker The propodeum is a term that can refer to unrelated structures in insects or in mollusks. Insects The first abdominal segment in Apocrita Hymenoptera (wasps, bees and ants) is known a ...

. On average, individual hairs are long. Golden, erect

setae In biology, setae (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae ...

are present under the head and on the mesosoma. The setae on the

tibia The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...

are short in comparison to setae on the mesosoma. The workers' eyes bulge while soldiers' eyes are flat. Within the ''Camponotus nigriceps'' species group, the black-headed sugar ant can be easily mistaken for a banded sugar ant due to its similar appearance, but the latter are darker and have a band wrapping around their gaster, a feature absent on the black-headed sugar ant. Minor worker specimens are usually examined when trying to identify similar-looking species.

Distribution and habitat

The black-headed sugar ant can be found in most Australian states. The species is restricted to the north and south-east of

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

, and is widespread throughout the

Australian Capital Territory The Australian Capital Territory (ACT), known as the Federal Capital Territory until 1938, is an internal States and territories of Australia, territory of Australia. Canberra, the capital city of Australia, is situated within the territory, an ...

. The ant is also widespread throughout

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

and

Victoria Victoria most commonly refers to: * Queen Victoria (1819–1901), Queen of the United Kingdom and Empress of India * Victoria (state), a state of Australia * Victoria, British Columbia, Canada, a provincial capital * Victoria, Seychelles, the capi ...

, but it is not found in the north-west of New South Wales and south-east of Victoria. In

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

, it is commonly seen in the south-eastern regions and less encountered in the north-west. Populations are present in

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

, but they are not found in either the north regions of the state or in the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

. Black-headed sugar ants mostly live in dry regions including dry sclerophyll woodland or open areas, particularly in

pastures Pasture (from the Latin ''pastus'', past participle of ''pascere'', "to feed") is land used for grazing. Types of pasture Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, c ...

. Other preferred habitats include mallee,

eucalyptus ''Eucalyptus'' () is a genus of more than 700 species of flowering plants in the family Myrtaceae. Most species of ''Eucalyptus'' are trees, often Mallee (habit), mallees, and a few are shrubs. Along with several other genera in the tribe Eucalyp ...

woodland and ''

Casuarina cristata ''Casuarina cristata'', commonly known as belah or muurrgu, is a species of flowering plant in the family Casuarinaceae and is endemic to inland eastern Australia. It is a tree with fissured or scaly bark, sometimes drooping branchlets, the lea ...

'' woodland, at elevations ranging . Nests are found in

laterite Laterite is a soil type rich in iron and aluminium and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. They develop by intensive and prolo ...

soil in

upland Upland or Uplands may refer to: Geography *Hill, an area of higher land, generally *Highland, an area of higher land divided into low and high points *Upland and lowland, conditional descriptions of a plain based on elevation above sea level *I ...

areas, surrounded by tall eucalyptus trees or under groves. Nests can also be found in large mounds or under stones. Sometimes,

cedar wood Cedar is part of the English common name of many trees and other plants, particularly those of the genus ''Cedrus''. Some botanical authorities consider the Old-World ''Cedrus'' the only "true cedars". Many other species worldwide with similarly ...

and large mounds occupied by the meat ant (''

Iridomyrmex purpureus The meat ant (''Iridomyrmex purpureus''), also known as the gravel ant or southern meat ant, is a species of ant endemic to Australia. A member of the genus ''Iridomyrmex'' in the subfamily Dolichoderinae, it was described by British entomolo ...

)'' are inhabited by black-headed sugar ants.

Behaviour and ecology

Black-headed sugar ants are

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

foragers of food. The species is sometimes considered a household pest since ants can enter human homes at night in search of food. During the day, these ants are not active and have exhibited sleep-like behaviours until it is night. The black-headed sugar ant predominantly feeds on sweet secretions and sugar water; insects and a variety of foodstuffs in human homes are also consumed. Workers use several social techniques during colony movements to other nest sites or to lead others to food sources, which includes a worker carrying another worker,

tandem running Tandem running is a pair movement coordination observed in ants and termites. In ants, tandem running is used for social learning, by which one ant leads another native ant from the nest to the food source it has found. Tandem running is also use ...

or laying down a

pheromone trail Trail pheromones are semiochemicals secreted from the body of an individual to affect the behavior of another individual receiving it. Trail pheromones often serve as a multi purpose chemical secretion that leads members of its own species towards a ...

for

orientation Orientation may refer to: Positioning in physical space * Map orientation, the relationship between directions on a map and compass directions * Orientation (housing), the position of a building with respect to the sun, a concept in building des ...

. They are also attendants to the butterflies '' Ogyris idmo'' and '' Ogyris genoveva''. The larvae will reside in underground areas constructed by attending ants, and during the night they will emerge with them and feed on

mistletoe Mistletoe is the common name for obligate parasite, obligate parasitic plant, hemiparasitic plants in the Order (biology), order Santalales. They are attached to their host tree or shrub by a structure called the haustorium, through which they ...

leaves. The species is tolerant to myrmecophiles; the beetles '' Ctenisophus morosus'' and '' Cryptodus paradoxus'' have been found in nests, and the wingless cricket '' Myrmecophilus australis'' also dwells inside colonies. Other insects which dwell inside nests include froghoppers in the family

Cercopidae Cercopidae are the largest family of Cercopoidea, a xylem-feeding insect group, commonly called froghoppers. They belong to the hemipteran suborder Auchenorrhyncha. A 2023 phylogenetic study of the family suggested the elevation of the New Worl ...

. Several birds and other predatory organisms prey on the black-headed sugar ant. Birds such as the black-faced woodswallow, rufous treecreeper, noisy miner, jacky winter and

southern scrub robin The southern scrub robin (''Drymodes brunneopygia'') is a species of bird in the family Petroicidae. It is endemism, endemic to Australia, where it occurs in mallee (habit), mallee and heathland in the semi-arid southern parts of the continent, e ...

prey on this species, as indicated by the fact that workers body parts have been found in the birds' stomach contents. Other predators of the black-headed sugar ant include the

rainbow trout The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributary, tributaries of the Pacific Ocean in North America and Asia. The steelhead (sometimes called steelhead trout) is an Fish migration#Classification, ...

most likely begins during summer, as a young mated queen with no brood was found in a freshly built chamber in January. During the early years of colony foundation, there are more soldiers, and older colonies may have a workforce consisting only of minor workers. A typical colony may contain five to seven thousand individuals. Queens of the species can live for an exceptionally long time; wild queens can live for up to 21 years with one known captive living to 23 years of age, making it the second oldest recorded ant queen. Larvae of this species can grow to be quite large; collected larvae reach lengths of .

Notes

References

Cited text

External links

''Camponotus nigriceps''
in the

Atlas of Living Australia The Atlas of Living Australia (ALA) is an online repository of information about Australian plants, animals, and fungi. Development started in 2006. The Commonwealth Scientific and Industrial Research Organisation (CSIRO) is an organisation sign ...